#!/usr/bin/env python
# For each given packageprefix, remove the files in the tree that it would
# collide with. This is useful if you're replacing a large port incrementally
# with smaller ones, or if you need to remove a port that's accidentally
# installed straight into the tree rather than the packageprefix.

from garstowlib import *
import os, sys, stat, re, fnmatch

def package_of(path):
	packagesdir = get_packages_dir()
	return re.sub(r'/.*$', r'', path[len(packagesdir) + 1:])

lib_portfile = Portfile(gar_dir + "/gar.lib.mk")

def is_exception(path):
	packagesdir = get_packages_dir()
	end = re.sub(r'^[^/]*/', r'', path[len(packagesdir) + 1:])
	cols = re.split(r'\s+', lib_portfile.variable("COLLISIONS"))
	for col in cols:
		if fnmatch.filter([end], col) != []:
			return True
	return False

def deconflict(pp, package, allow):
	prefix = get_stow_dir()
	packagesdir = get_packages_dir()
	f = os.popen("find " + pp + " -not -type d", "r")
	for l in f.readlines():
		l = l[:-1]
		if not l.startswith(pp):
			die("Bad thing found: " + l)
		l = get_stow_dir() + l[len(pp):]
		try:
			os.lstat(l)
		except OSError:
			# File doesn't exist.
			continue
		link = l
		while 1:
			is_link = stat.S_ISLNK(os.lstat(link).st_mode)
			if is_link:
				rl = norm_readlink(link)
			if is_link and rl.startswith(packagesdir):
				realpath = rl + l[len(link):]
				conf_package = package_of(realpath)
				if conf_package != package:
					if conf_package not in allow and not is_exception(realpath):
						die("Trying to remove file from non-allowed package " + conf_package + ": " + realpath)
					print "Removing packaged file in package " + conf_package + ": " + realpath
					os.unlink(realpath)
					if link == l:
						print "Removing link: " + l
						os.unlink(l)
				break
			link = os.path.dirname(link)
			if link == prefix:
				print "Removing unstowed file: " + l
				os.unlink(l)
				break
	f.close()

if __name__ == "__main__":
	if len(sys.argv) < 3:
		die("Usage: force-deconflict packageprefix package [allow-removal-from-package ...]")
	pp = sys.argv[1]
	package = sys.argv[2]
	allow = sys.argv[3:]
	if pp.endswith("/"):
		pp = pp[:-1]
	if not pp.startswith(get_packages_dir()):
		die(pp + " is not a package dir")
	deconflict(pp, package, allow)